Table of Contents
What is Kubernetes self-healing?
One of the great benefits of Kubernetes is its self-healing ability. If a containerized app or an application component goes down, Kubernetes will instantly redeploy it, matching the so-called desired state. In fact, Kubernetes provides self-healing by default.
Can a pod self heal itself?
Pods do not, by themselves, self-heal. If a Pod is scheduled to a node that then fails, the Pod is deleted; likewise, a Pod won’t survive an eviction due to a lack of resources or Node maintenance.
What is the purpose of pods in Kubernetes?
Pods are the smallest, most basic deployable objects in Kubernetes. A Pod represents a single instance of a running process in your cluster. Pods contain one or more containers, such as Docker containers. When a Pod runs multiple containers, the containers are managed as a single entity and share the Pod’s resources.
What does a deployment automatically create?
The Deployment automatically replaces Pods that fail or are evicted from their nodes. In this example: A Deployment named nginx is created, indicated by the metadata: name field. The Deployment creates three replicated Pods, indicated by the replicas field.
What is a K8s cluster?
A Kubernetes cluster is a set of nodes that run containerized applications. Containerizing applications packages an app with its dependences and some necessary services. Kubernetes clusters allow containers to run across multiple machines and environments: virtual, physical, cloud-based, and on-premises.
What is terminationGracePeriodSeconds?
concept terminationgraceperiodsecond in category kubernetes The application is given a certain amount of time to terminate. This time can be configured using the terminationGracePeriodSeconds field in the pod’s spec and defaults to 30 seconds.
Is Kubernetes reliable?
Kubernetes helps improve reliability by providing redundant components, and making it possible to schedule application containers across multiple nodes and multiple availability zones (AZs) in the cloud.
What is a label in Kubernetes?
Labels are key/value pairs that are attached to Kubernetes objects, such as pods (this is usually done indirectly via deployments). Labels are intended to be used to specify identifying attributes of objects that are meaningful and relevant to users. Labels can be used to organize and to select subsets of objects.
Why pod is smallest unit in Kubernetes?
A Kubernetes pod is a collection of one or more Linux® containers, and is the smallest unit of a Kubernetes application. Any given pod can be composed of multiple, tightly coupled containers (an advanced use case) or just a single container (a more common use case).
What is a k8s deployment?
A Kubernetes deployment is a resource object in Kubernetes that provides declarative updates to applications. A deployment allows you to describe an application’s life cycle, such as which images to use for the app, the number of pods there should be, and the way in which they should be updated.
What is k8s service?
A Kubernetes service is a logical abstraction for a deployed group of pods in a cluster (which all perform the same function). Since pods are ephemeral, a service enables a group of pods, which provide specific functions (web services, image processing, etc.) to be assigned a name and unique IP address (clusterIP).